Immature oocyte incidence: Contributing factors and effects on mature sibling oocytes in intracytoplasmic sperm injection cycles

The Effect of Wharton's Jelly-Derived Conditioned Medium on the In Vitro Maturation of Immature Oocytes, Embryo Development, and Genes Expression Involved in Apoptosis

Oocyte cytoplasmic maturation is a crucial process during in vitro maturation (IVM), and finding an appropriate IVM medium that promotes oocyte competence is very critical in assisted reproductive technology (ART). The aim of this study was to investigate the effects of umbilical cord Wharton's jelly (WJ-MSCs)-derived conditioned media on the maturation of immature oocytes and their developmental potential in humans after IVM, as well as apoptotic gene expression. A total of 392 germinal vesicle (GV) oocytes were collected from 207 women aged 25-35 years and divided into two IVM groups: (1) control group, which was cultured in CleavTM medium, and (2) experimental group, which was cultured in supernatants of umbilical cord Wharton's jelly as a conditioned medium (CM). First, WJ-MSCs were isolated, and their purity was analyzed. The immunophenotypes of WJ-MSCs were analyzed by flow cytometry. The quantitative expression of BCL2, BAX, and BAG1 in matured oocytes and embryos was evaluated through quantitative real-time polymerase chain reaction (qRT-PCR). Our findings showed that WJ-MSCs have a high proliferating capacity. The purity of the isolated cells was further validated by immunophenotyping, which revealed that their surface antigen expression had phenotypical properties similar to WJ-MSCs. When compared to CD34 and CD45 surface markers, the enlarged cells were positive for CD90, CD105, and CD44. There were significant differences in cytoplasmic maturation of oocytes and embryo quality between the two groups. The mRNA expression levels of BCL-2, BAG1, and BAX in matured oocytes and embryos were also significantly different between the two groups. Therefore, WJ-MSCs medium indicated potential efficacy in terms of ameliorating oocyte maturation and in promoting the development and genes expression of BAX, BCL-2, and BAG1.

Twelve Hours Post-Injection Serum Human Chorionic Gonadotropin and Body Mass Index Predicts In Vitro Fertilization Oocyte Maturation Rate: A Cross-Sectional Study

BACKGROUND

In vitro fertilization (IVF) remains a main treatment for infertility cases. Post-injection human chorionic gonadotropin (hCG) level is an essential factor in determining oocyte maturation rate in IVF. This study aimed to determine the relationship between 12 hours post-injection serum hCG level and oocyte maturation rate among IVF participants.

MATERIALS AND METHODS

A cross-sectional study on IVF participants was done at a tertiary hospital in Indonesia from January 2020 to December 2021. Subjects were injected with 250 μg of recombinant-hCG (r-hCG) subcutaneously. Twelve hours post-injection serum hCG levels and oocyte maturation rate data were retrieved and analyzed accordingly.

RESULTS

Twenty-eight subjects were recruited into the study. Higher 12 hours post-injection serum hCG was related to oocyte maturation rate (P=0.046). The cut-off point of 12 hours post-injection serum hCG to predict better oocyte maturation rate was 90.15 mIU/mL (sensitivity 68.2%, specificity 83.3%). Oocyte maturation rate may be predicted using body mass index (BMI) and 12 hours post-injection serum hCG.

CONCLUSION

Higher 12 hours post-injection serum hCG was associated with a higher oocyte maturation rate in IVF subjects.

Rescue IVM of Denuded GV- and MI-Stage Oocytes of Premenopausal Rats with Oncostatin M, Insulin-like Growth Factor I, and Growth Hormone

Immature oocytes are retrieved and matured through in vitro maturation (IVM). Maturation, fertilization rates, and embryo development via IVM are all lower than those found in vitro fertilization (IVF) cycles. We investigated the effects of oncostatin M (OSM), insulin-like growth factor-1 (IGF-I), and growth hormone (GH) in rescue IVM. A total of 111 germinal vesicle (GV) and 17 metaphase I (MI) oocytes were obtained after conventional IVF from 28 female Wistar albino rats. Denuded immature oocytes were cultured in maturation medium supplemented with OSM, IGF-1, or GH. The quantities of metaphase II (MII) oocytes matured from the GV stage were 17 of 30 (56.6%), 15 of 28 (53.5%), 10 of 30 (33.3%), and 7 of 23 (30.3%), in control, OSM, IGF-I, and GH groups, respectively. Maturation rates in control and OSM groups were higher than those in IGF-I and GH groups (p = 0.001). The quantities of MII oocytes matured from MI stage were 7 of 7 (100%), 4 of 4 (100%), 1 of 1 (100%), and 1 of 5 (20%) in control, OSM, IGF-I, and GH groups, respectively. Maturation rates from MI to MII stages in control, OSM, and IGF-I groups were higher than those in the GH group (p = 0.004). Acceptable maturation rates are observed with OSM in rat oocytes in rescue IVM.

GVBD rate is an independent predictor for pregnancy in ICSI patients with surplus immature oocytes

INTRODUCTION

It was reported that there were still up to 30% immature retrieved oocyte at germinal vesicle (GV) or metaphase I (MI) stage. Whether the spontaneous maturity competency of immature oocytes associated to the clinical outcome of in vitro fertilization (IVF) cycles remains unclear and unexplored. This study aimed to investigate how the oocyte developmental parameters in in vitro maturation (IVM) affect clinical outcomes of intracytoplasmic sperm injection (ICSI) cycles.

METHODS

This retrospective cohort study included couples undergoing ICSI in a university-affiliated hospital. Surplus immature oocytes during ICSI were collected and cultured in vitro. The numbers of germinal vesicle (GV) oocytes undergoing GV breakdown (GVBD) and polar body 1 extrusion within 24 h culture were recorded. The main outcome measurements were demographic baselines and oocyte developmental parameters in IVM associated with pregnancy outcomes.

RESULTS

A total of 191 couples were included with an overall GVBD rate of 63.7% (327/513) and oocyte maturation rate of 46.8% (240/513). 53.4% (102/191) of them had embryos transferred freshly, which originated from metaphase II oocytes that matured spontaneously in vivo, and 60.8% (62/102) got pregnant. Among factors with a P-value < 0.2 in univariate logistic regression analyses of pregnancy correlation, GVBD rate (OR 3.220, 95% CI 1.060-9.782, P=0.039) and progesterone level on human chorionic gonadotropin (HCG) day (OR 0.231, 95% CI 0.056-0.949, P=0.042) remained significant in the multivariate model. The area under the curve (AUC) of the predictive nomogram was 0.729 (95% CI 0.632-0.826) with an acceptable calibration. Moreover, decision curve analyses illustrated the superior overall net benefit of models that included the GVBD rate in clinical decisions within a wide range of threshold probabilities.

CONCLUSION

In conclusion, GVBD rate and progesterone level on HCG day may be associated with pregnancy outcomes in infertile couples during the regular ICSI procedure. An elevated GVBD rate within 24 h may greatly increase the likelihood of pregnancy in infertile couples during ICSI. This preliminary study may optimize clinical pregnancy prediction, which provides support in decision-making in clinical practice.

Oocyte Competence Biomarkers Associated With Oocyte Maturation: A Review

Oocyte developmental competence is one of the determining factors that influence the outcomes of an IVF cycle regarding the ability of a female gamete to reach maturation, be fertilized, and uphold an embryonic development up until the blastocyst stage. The current approach of assessing the competency of an oocyte is confined to an ambiguous and subjective oocyte morphological evaluation. Over the years, a myriad of biomarkers in the cumulus-oocyte-complex has been identified that could potentially function as molecular predictors for IVF program prognosis. This review aims to describe the predictive significance of several cumulus-oocyte complex (COC) biomarkers in evaluating oocyte developmental competence. A total of eight acclaimed cumulus biomarkers are examined in the study. RT-PCR and microarray analysis were extensively used to assess the significance of these biomarkers in foreseeing oocyte developmental competence. Notably, these biomarkers regulate vital processes associated with oocyte maturation and were found to be differentially expressed in COC encapsulating oocytes of different maturity. The biomarkers were reviewed according to the respective oocyte maturation events namely: nuclear maturation, apoptosis, and extracellular matrix remodeling, and steroid metabolism. Although substantial in vitro evidence was presented to justify the potential use of cumulus biomarkers in predicting oocyte competency and IVF outcomes, the feasibility of assessing these biomarkers as an add-on prognostic procedure in IVF is still restricted due to study challenges.

The usefulness of metaphase I oocytes in women who undergo controlled ovarian hyperstimulation for intracytoplasmic sperm injection

Objective:

The aim of this study was to evaluate the fertilization and blastocyst formation rates of oocytes in metaphase I (MI) obtained from women who underwent controlled ovarian hyperstimulation (COH) for intracytoplasmic injection.

Methods:

A prospective cohort study that included women from whom at least 1 MI and 1 MII oocyte were obtained after COH was performed. We collected 1,907 oocytes from 164 women (1291 MII, 352 MI and 258 prophase I or atretic). After oocyte classification, the MII and MI oocytes were incubated for 4 hours.

Results:

After 4 hours, the rescue maturation rate was 57.2%; 205 MI oocytes matured to MII oocytes in vitro (rescued MI-MII group), and 153 remained in MI (arrested MI group). The normal fertilization rates were directly associated with oocyte maturation, with rates of 79.1%, 60.2%, and 31.9% in MII, MI-MII and MI oocytes, respectively (p<0.001). Group arrested MI had an odds ratio (OR) of 7.6 (CI 5.2 - 11.2, p<0.001) for abnormal fertilization compared with Group MII. The blastocyst formation rate was directly associated with oocyte maturation, at 36.4% for MII, 11.4% for MI-MII and 0.6% for MI.

Conclusion:

Oocytes collected at the MI stage after OCH that did not mature to MII after rescue maturation had a blastocyst formation rate of only 0.6%, while those in MII and MI-MII had rates of 36.4% and 11.4%, respectively. However, we found a pregnancy with the birth of a healthy baby from a blastocyst formed after intracytoplasmic sperm injection (ICSI) of an MI oocyte.